Publish a tested JSON Schema for base_manifest.yaml

[codeforester]

Goal

Publish a tested JSON Schema for base_manifest.yaml so users and editors receive validation and completion before invoking Base.

Background

Base has a runtime manifest parser and schema_version, but no formal JSON Schema artifact or editor integration. The manifest now covers project metadata, artifacts, IDEs, health, commands, activation, Python, GitHub, demo, build, release, and other sections. Runtime-only validation makes discovery slower and increases the risk of documentation/parser drift.

#319 introduced the schema-version marker; it did not add a formal schema. Output stability work in #1579 concerns CLI JSON payloads, not the YAML manifest contract.

Scope

• Produce a JSON Schema for the current base_manifest.yaml contract.
• Generate the schema from runtime definitions, or otherwise establish one authoritative source rather than a second hand-maintained schema.
• Validate representative accepted and rejected fixtures against both the runtime parser and JSON Schema.
• Document YAML language server, VS Code, and repository-local schema association.
• Define compatibility expectations between manifest schema_version and published schema versions.
• Add a release/check mechanism that catches schema/parser drift.

Acceptance Criteria

• A versioned schema artifact is committed and linked from manifest documentation.
• Editors can provide completion and validation for a Base manifest using documented configuration.
• Shared fixtures produce compatible results in the JSON Schema and runtime parser.
• Unsupported future schema versions remain fail-closed.
• CI fails when the published schema drifts from covered runtime behavior.

Validation

• Schema validator tests over accepted and rejected fixtures.
• Existing manifest parser tests.
• Documentation link validation where available.
• git diff --check.

Non-Goals

• Do not replace runtime validation with editor validation.
• Do not submit to a public schema registry until the local contract is stable.
• Do not add new manifest capabilities merely to complete the schema.

Project Fields

• Status: Backlog
• Priority: P2
• Size: M
• Area: Manifest
• Initiative: Adoption Polish

Agent Assignment

Human first for the source-of-truth decision; fixture and editor-documentation slices can then be agent-ready.